By 40 weeks, the average baby weighs 3.619kg (7.98lb), and is about 51cm long from head to heel. But how big is your baby ...

The charts below give you an idea of how your child's weight and height (or length, for babies) compare to the average weight and height of kids in their age group. The numbers in these charts are ...

To see if your child is too skinny or overweight, there is a "weight for height" chart or a "BMI" index. These tell if your child's weight is close to what it should be, given her height.